Different SEO tools hold different meanings for different web masters and it is really difficult to compile a list of the best SEO tools. But still I'd like to share a nice article best seo tools for 2009, worth a read -http://www.iintense.com/best-seo-tools-for-2009/

I think SENuke is one of the best SEO tools. It makes so easy to submit your site in various bookmarking sites. There are also many options like RSS submission, creating social mediate pages, video submission, etc. which save your lots of times. However, it's a paid tool.